Are steel valve covers prone to leaks or a myth? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**IT Cowboy** · 03-17-2026, 02:34 PM

Are the steel OEM valve covers as prone to leaks as usually mentioned or is it a myth from mostly wrong installation.

Are they really that touchy if they are straight, and installed using a modern gasket and spreaders and not over torqued . Is it better to use the gaskets with the metal inserts better or is a thinner old school gasket better so they would be more flat when tightened down.

**70STOVEBOLT** · 03-17-2026, 02:48 PM

If the flanges are straight, they do not leak. Most guys will overtighten them and distort the flange, then they don't seal. They only need to be snugged good, I think the factory torque rating is something like 6 or 8 ft lbs. I like the Fel-Pro Permadry Plus gaskets with the torque limiters built in (metal inserts). They can be reused many times, ideal for engines with solid lifters.

**IT Cowboy** · 03-17-2026, 03:45 PM

So would I be better off buying a new set of reproduction ones as they would be more likely to be straight and not messed up near the bolt holes. I am seeing all kinds of used OEM ones for sale on fleabay but would they be warped or abused?

**71CHEVYSHORTBED402** · 03-17-2026, 05:34 PM

Quote:

Originally Posted by IT Cowboy

So would I be better off buying a new set of reproduction ones as they would be more likely to be straight and not messed up near the bolt holes. I am seeing all kinds of used OEM ones for sale on fleabay but would they be warped or abused?

Reproduction? Blasphemy!

Flatten them with a straight 2x4 or something. The heads do not lie, if they sit without any rocking you should be good

Rich69shortfleet · 03-17-2026, 06:35 PM

Chrome valve covers are more prone to leaks.

But, overall, do yourself a favor, glue the gaskets to the valve covers with weather strip adhesive or RTV, let them cure over night before installing them to the engine.

**Sheepdip** · 03-18-2026, 04:23 PM

I went to an aftermarket LT-1 type stock height aluminum valve covers. I used silicone and a nice thick cork gasket, clamped them down overnite before installing them.
So far 1 year leak free.

**IT Cowboy** · 03-18-2026, 05:23 PM

I sort of want orange ones to look like original but my aluminum ones now do not leak so I might just let that sleeping dog be

**mr48chev** · 03-18-2026, 07:46 PM

The proper valve cover retainers help a lot with stock valve covers.

Cleanup when you replace the gaskets is a mess but years ago a friend taught me that using CAT (as in Caterpillar equipment) contact cement Between the gasket and the valve cover and silicone gasket sealer between the gasket and the head seal things up pretty well.

I've got a pair of cheapie chrome valve covers out in the shed that I'll give to someone's kid to make valve cover racers out of as that is all they are good for. on my 350 I finally bought a pair of fabricated aluminum valve covers off Ebay that are what don't leak.

**70STOVEBOLT** · 03-21-2026, 04:58 PM

Quote:

Originally Posted by IT Cowboy

I sort of want orange ones to look like original but my aluminum ones now do not leak so I might just let that sleeping dog be

If you don’t have to have the original look, keep the aluminum covers, those usually don’t leak.

**mike16** · 03-21-2026, 09:44 PM

Myth

ivory68 · 03-23-2026, 07:39 PM

I've used PML valve covers for years. Zero leaks. The flanges are really thick and stiff. I use steel core rubber gaskets from Summit and put a thin coat of RTV on both sides. I've had leaks with stock steel, Edelbrock chrome, and M/T aluminum covers.

PML will also power coat.
https://yourcovers.com/storefront.html

**70STOVEBOLT** · 03-23-2026, 08:43 PM

Let’s see em ivory68!

**Steeveedee** · 03-23-2026, 09:19 PM

Tin valve covers used to leak like crazy. As has been mentioned, guys tightened the bolts too much. #1 complaint at Chevy dealers I worked at in the early '70s was oil leaks. It didn't help that a tune-up in those days called for re-torquing the head bolts. This required removing the valve covers. Over-torquing was always an issue.

ivory68 · 03-23-2026, 09:41 PM

Quote:

Originally Posted by 70STOVEBOLT

Let’s see em ivory68!

Haha, here you go. I bought the natural finish (unpainted). I used rattle can wrinkle finish (Krylon), and sanded down the fins and lettering. The wrinkle finish is very TOUGH. Never chipped, peeled, bubbled, or scratched. The flange is very thick- at least 1/4" thick. Not much room for nuts or bolt heads. Had to use socket head cap screws.

**Steeveedee** · 03-23-2026, 10:12 PM

^ I love those finned alloy valve covers! Wife doesn't want anything changed on her "daddy's" truck, in spite of all the cheapo crap from J.C. Whitney that he put on it. Go figure.

**70STOVEBOLT** · 03-24-2026, 12:36 PM

Quote:

Originally Posted by Steeveedee

^ I love those finned alloy valve covers! Wife doesn't want anything changed on her "daddy's" truck, in spite of all the cheapo crap from J.C. Whitney that he put on it. Go figure.

Lol

03-17-2026, 02:48 PM	#2
70STOVEBOLT Senior Member Join Date: Jun 2005 Location: Winona Lake, IN Posts: 7,062	Re: Are steel valve covers prone to leaks or a myth? If the flanges are straight, they do not leak. Most guys will overtighten them and distort the flange, then they don't seal. They only need to be snugged good, I think the factory torque rating is something like 6 or 8 ft lbs. I like the Fel-Pro Permadry Plus gaskets with the torque limiters built in (metal inserts). They can be reused many times, ideal for engines with solid lifters. __________________ 70 C/10 SWB 402/TH400/3.73 "The Needy Beast" 200,000 Mile Club Disc Brake Club Owner installed options: Front Sway Bar Power Steering Power Brakes Cigar Lighter Courtesy Lights Deluxe Side Markers Wiper Delay Sliding Rear Window Power Windows Power Locks Sniper EFI 2015 Silverado 1500 LS 4.3/6L80/3.23 lowered 2" front & rear

03-17-2026, 03:45 PM	#3
IT Cowboy Senior Member Join Date: Jan 2025 Location: Arizona in a van down by the river Posts: 617	Re: Are steel valve covers prone to leaks or a myth? So would I be better off buying a new set of reproduction ones as they would be more likely to be straight and not messed up near the bolt holes. I am seeing all kinds of used OEM ones for sale on fleabay but would they be warped or abused? __________________ 1972 C10 Custom Deluxe Highlander 402 Freedom isn't safe, it requires you to take responsibility for your own life, your own safety, and your own success. It carries with it the possibility of failure and the understanding that you're working without out a safety net. If you give the state the responsibility for any of these you also give up the freedom that accompanies the responsibility.

03-17-2026, 06:35 PM	#5
Rich69shortfleet Registered User Join Date: May 2016 Location: Waverly, NE Posts: 562	Re: Are steel valve covers prone to leaks or a myth? Chrome valve covers are more prone to leaks. But, overall, do yourself a favor, glue the gaskets to the valve covers with weather strip adhesive or RTV, let them cure over night before installing them to the engine. __________________ 1965 Malibu SS L79 Restoration Page 2004 Torrid Red GTO Preservation Page 2006 Brazen Orange GTO Preservation Page Rich Cummings

03-18-2026, 04:23 PM	#6
Sheepdip Senior Member Join Date: Nov 2018 Location: Waterford California Posts: 2,892	Re: Are steel valve covers prone to leaks or a myth? I went to an aftermarket LT-1 type stock height aluminum valve covers. I used silicone and a nice thick cork gasket, clamped them down overnite before installing them. So far 1 year leak free.

03-18-2026, 05:23 PM	#7
IT Cowboy Senior Member Join Date: Jan 2025 Location: Arizona in a van down by the river Posts: 617	Re: Are steel valve covers prone to leaks or a myth? I sort of want orange ones to look like original but my aluminum ones now do not leak so I might just let that sleeping dog be __________________ 1972 C10 Custom Deluxe Highlander 402 Freedom isn't safe, it requires you to take responsibility for your own life, your own safety, and your own success. It carries with it the possibility of failure and the understanding that you're working without out a safety net. If you give the state the responsibility for any of these you also give up the freedom that accompanies the responsibility.

03-17-2026, 02:34 PM	#1
IT Cowboy Senior Member Join Date: Jan 2025 Location: Arizona in a van down by the river Posts: 617	Are steel valve covers prone to leaks or a myth? Are the steel OEM valve covers as prone to leaks as usually mentioned or is it a myth from mostly wrong installation. Are they really that touchy if they are straight, and installed using a modern gasket and spreaders and not over torqued . Is it better to use the gaskets with the metal inserts better or is a thinner old school gasket better so they would be more flat when tightened down. __________________ 1972 C10 Custom Deluxe Highlander 402 Freedom isn't safe, it requires you to take responsibility for your own life, your own safety, and your own success. It carries with it the possibility of failure and the understanding that you're working without out a safety net. If you give the state the responsibility for any of these you also give up the freedom that accompanies the responsibility.

03-18-2026, 07:46 PM	#8
mr48chev Registered User Join Date: Jul 2007 Location: Toppenish, WA Posts: 16,391	Re: Are steel valve covers prone to leaks or a myth? The proper valve cover retainers help a lot with stock valve covers. Cleanup when you replace the gaskets is a mess but years ago a friend taught me that using CAT (as in Caterpillar equipment) contact cement Between the gasket and the valve cover and silicone gasket sealer between the gasket and the head seal things up pretty well. I've got a pair of cheapie chrome valve covers out in the shed that I'll give to someone's kid to make valve cover racers out of as that is all they are good for. on my 350 I finally bought a pair of fabricated aluminum valve covers off Ebay that are what don't leak. Attached Images __________________ Founding member of the too many projects, too little time and money club. My ongoing truck projects: 48 Chev 3100 that will run a 292 Six. 71 GMC 2500 that is getting a Cad 500 transplant. 77 C 30 dualie, 454, 4 speed with a 10 foot flatbed and hoist. It does the heavy work and hauls the projects around.

03-21-2026, 09:44 PM	#10
mike16 Senior Member Join Date: Dec 2009 Location: bisbee, arizona Posts: 1,609	Re: Are steel valve covers prone to leaks or a myth? Myth

03-23-2026, 07:39 PM	#11
ivory68 Registered User Join Date: Oct 2013 Location: San Diego, Ca Posts: 30	Re: Are steel valve covers prone to leaks or a myth? I've used PML valve covers for years. Zero leaks. The flanges are really thick and stiff. I use steel core rubber gaskets from Summit and put a thin coat of RTV on both sides. I've had leaks with stock steel, Edelbrock chrome, and M/T aluminum covers. PML will also power coat. https://yourcovers.com/storefront.html

03-23-2026, 08:43 PM	#12
70STOVEBOLT Senior Member Join Date: Jun 2005 Location: Winona Lake, IN Posts: 7,062	Re: Are steel valve covers prone to leaks or a myth? Let’s see em ivory68! __________________ 70 C/10 SWB 402/TH400/3.73 "The Needy Beast" 200,000 Mile Club Disc Brake Club Owner installed options: Front Sway Bar Power Steering Power Brakes Cigar Lighter Courtesy Lights Deluxe Side Markers Wiper Delay Sliding Rear Window Power Windows Power Locks Sniper EFI 2015 Silverado 1500 LS 4.3/6L80/3.23 lowered 2" front & rear

03-23-2026, 09:19 PM	#13
Steeveedee Ram-A-Lam-A-Ding-Dong Join Date: Jan 2013 Location: Simi Valley, CA Posts: 11,899	Re: Are steel valve covers prone to leaks or a myth? Tin valve covers used to leak like crazy. As has been mentioned, guys tightened the bolts too much. #1 complaint at Chevy dealers I worked at in the early '70s was oil leaks. It didn't help that a tune-up in those days called for re-torquing the head bolts. This required removing the valve covers. Over-torquing was always an issue. __________________ ~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA

03-23-2026, 10:12 PM	#15
Steeveedee Ram-A-Lam-A-Ding-Dong Join Date: Jan 2013 Location: Simi Valley, CA Posts: 11,899	Re: Are steel valve covers prone to leaks or a myth? ^ I love those finned alloy valve covers! Wife doesn't want anything changed on her "daddy's" truck, in spite of all the cheapo crap from J.C. Whitney that he put on it. Go figure. __________________ ~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.